A Clinical core will be established to provide critical services and resources to the scientific to the scientific projects. Specifically, the Core will provide: 1) a human genital tract tissue bank and clinical specimen repository, 2) and specimen processing for immunohistology, in situ hybridization, and PCR/RT-PCR based investigations, 3) a PCR STD screening service to detect STD pathogens in tissues and clinical samples, 4) an epithelial cell culture core which will establish and characterize primary and immortalized cell lines from penile urethra, prostrate and seminal vesicles, and 5) a unified database and statistics service. All three of the scientific project for studies on the relative abundance of lymphocyte subsets, immunoregulatory molecules, immunoglobulin subclasses, defensins and mucins in various sites of the distal male genital tract and the effects of specific genital tract infections on levels of these mediators. Definition of the types of STD pathogens in these tissues and clinical specimens by culture and PCR techniques will refine correlations that can be made, and the unified database will integrate research findings from the three projects. In addition, all projects will utilize our unique epithelial cell line infection models to study molecular mechanisms of pathogen-epithelial interactions that affect mucosal defense.